Where the recovery is happening — and where it is not.
The Indian River Lagoon’s 72% seagrass rebound between 2023 and 2025 was not uniform across the system. Five of the six sub-lagoons grew. One shrank. This page walks through the basin-by-basin data, what SOIRL has spent in each one, and what the science honestly does and does not tell us about causation.
What the state scientist actually said.
When the St. Johns River Water Management District released the 2025 seagrass mapping data in May 2026, supervising environmental scientist Lorae Simpson made two statements that need to be held together, not one or the other in isolation:
“It points to improvements in water quality, but I also want to caution this: we are still 42% behind the seagrass coverage that we had in 2009 and 2007.”
“Perhaps the most surprising finding in the new data is that the seagrass recovery appears to be entirely natural.”
Lorae Simpson, SJRWMD Governing Board briefing, May 12, 2026. (ClickOrlando/WKMG coverage →)
Those two statements are the honest baseline. I am not going to over-claim in either direction on this page. What I can do is walk through the data basin by basin and lay out what is documented, what is correlated, and what remains scientific work still to be done.
Not one lagoon. Six sub-basins, each with its own story.
The Indian River Lagoon system is divided by SJRWMD and FDEP into six mapped sub-basins for management and monitoring purposes. Brevard County covers roughly the northern three-quarters of the system (Mosquito, Banana River, North IRL, and much of Central IRL). SOIRL funds only apply to Brevard’s share.
On a phone, scroll the table sideways to see all columns.
Sources: SJRWMD 2025 seagrass mapping release (May 2026); Vero News on SCIRL acreage change; ClickOrlando/WKMG May 2026 briefing coverage; Marine Resources Council 2025 IRL Report Card (2021→2023 trend context).
The money side of the ledger.
SOIRL applies only to Brevard County — roughly Mosquito Lagoon (northern edge), Banana River Lagoon, North IRL, and the Brevard portion of Central IRL. Southern Central IRL and Southern IRL are outside Brevard’s taxing authority; those sub-basins have their own recovery drivers (state BMAPs, Indian River / St. Lucie / Martin / Palm Beach county programs, DEP grants, natural cycles).
Program-wide totals, as of the February 2026 Citizen Oversight Committee report:
- $504 million total SOIRL revenue since program inception (2017 through Nov 2025 collections)
- 403 projects approved in the 2026 project plan update
- 178,966 lbs/year annual estimated nitrogen reduction from projects completed or underway
- 143,807 lbs one-time nitrogen removal (muck dredging, etc.)
- 1,000,000+ lbs total nitrogen reduction estimated across all completed and underway projects (cumulative)
The 2026 update allocates the trust fund as follows:
- $233M (42%) — human wastewater: septic-to-sewer, package plant consolidation, WWTF upgrades, septic-lateral repair
- $213M (38%) — muck removal, including nutrient stripping from dredge outflow
- $86.6M (16%) — stormwater treatment and vegetation harvesting
- $11M (2%) — habitat restoration (oyster, seagrass planting, living shorelines)
- $10M (2%) — monitoring and project-performance measurement
- $4M (<1%) — public outreach
Sources: Brevard Legistar #8632 — 2026 SOIRL Plan Update; Lagoon Loyal COC meeting highlights (Feb 2026).
How much of the state-mandated pollution-reduction target has actually been hit?
Under Florida’s Basin Management Action Plan (BMAP) system, each sub-basin has a legally-set nitrogen and phosphorus reduction target that local governments and the state are collectively required to meet. FDEP tracks progress toward those targets across every project (SOIRL, state grants, city and county capital projects, private conservation) — not just SOIRL. The most recent public numbers are from FDEP’s 2017 IRL BMAP progress reporting; updated 2025–2026 numbers are still being compiled by FDEP:
On a phone, scroll the table sideways to see all columns.
Source: FDEP 2017 IRL BMAP progress bulletin; FDEP 2020 nitrogen/phosphorus allocations for IRL.
The pattern here is important: the sub-basins with the highest percentages of BMAP nitrogen-reduction target hit (North IRL Zone A and Zone B) are also the sub-basins showing among the strongest 2021–2025 seagrass recovery (Mosquito, North IRL, Banana River). The sub-basin with the lowest quantified reductions (Central IRL) is the one that showed the ~2% seagrass decline between 2023 and 2025. This is correlation, not proof of causation, but it is the pattern you would expect if nitrogen-reduction work were part of what enabled the recovery.
What I cannot claim from this data.
Correlation is not causation. Several confounders make it hard to attribute recovery to any single program:
- Two calm hurricane seasons. 2023 and 2024 delivered relatively mild storm systems in the IRL. Hurricanes disrupt seagrass beds directly (turbidity, uprooting) and indirectly (dumping large loads of stormwater and untreated nutrients into the lagoon). Calm hurricane seasons help recovery on their own, independent of any pollution-reduction work.
- Manatee-grazing reduction. The 2020–2022 manatee mortality event, tragic as it was, had the paradoxical downstream effect of temporarily reducing seagrass grazing pressure while beds tried to re-establish. NASA contractors observed manatees grazing Mosquito Lagoon beds in 2023, yet those beds still expanded — but the reduced grazing biomass overall in 2021–2022 gave seedling grass a window it might not otherwise have had.
- Natural cycles in water clarity. Brown-tide, green-tide, and blue-green algae blooms in the lagoon are driven by a combination of nutrients, temperature, salinity, and species-composition dynamics that scientists still do not fully model. Two years of relatively low bloom activity would improve water clarity and allow seagrass regrowth even in the absence of any nutrient-reduction work.
- SOIRL is not the only program. Nutrient reductions in each sub-basin come from a combination of SOIRL, FDEP state grants, city and county capital projects, private conservation, federal NEP funding, and homeowner behavior change. Even where reductions have measurably occurred, isolating SOIRL’s specific contribution requires basin-by-basin, project-by-project analysis that has not been completed to peer-reviewed standard.
- SJRWMD’s own scientist called the recovery “natural.” As quoted at the top of this page. That statement should be read carefully — “natural” in this context means “not driven by human seagrass replanting or transplant projects,” not “nutrient reductions had no role.” But it is a real, important caution against overclaiming.
This is why the honest phrasing on this site is: the expansion is occurring while major nutrient-reduction and habitat-restoration projects are underway. The correlation is real. The pattern by sub-basin is suggestive. The proof of causation is not yet in the peer-reviewed literature.
The ballot is not “did SOIRL cause the recovery.” The ballot is “what happens if this stops.”
This is the important part. The seagrass mapping data cannot yet prove that SOIRL caused the 2023–2025 recovery. But the ballot question is not whether SOIRL caused past recovery. The ballot question is whether Brevard continues investing in the categories of work — septic-to-sewer, muck removal, stormwater, plant upgrades — that every serious lagoon scientist agrees are necessary preconditions for continued recovery.
Two things are simultaneously true:
- The recovery might be partly natural. Calm hurricanes and manatee-die-off dynamics helped. Nutrient-reduction work probably helped. Attribution is complicated.
- The recovery is fragile either way. One bad summer of high nutrient loading can reverse it. If SOIRL projects stop and nutrient loading rises again, natural cycles alone will not save the lagoon.
In other words: the causal share attributable to SOIRL-funded reductions in the observed recovery is genuinely uncertain. What is not uncertain is the underlying nutrient science: excess nitrogen and phosphorus feed the algal blooms that shade out seagrass, and reducing those inputs is the mechanism by which every partner — SOIRL, state BMAPs, IRLNEP, MRC, and the estuary’s natural resilience — has been trying to restore the lagoon.